Abstract
Vestibular lithiasis (canalolithiasis as well as cupulolithiasis) commonly exists
in monocanalicular forms involving one of the three semicircular canals, frequent
posterior, less frequent horizontal, and very rarely anterior. It is treated with
canal clearing maneuvers intended to reposition the otoconia from the semicircular
canal (where they have inappropriately entered) through the utricular exit in the
nonampullary arm of the semicircular canal to the utricle (where they normally remain
as a part of utricular gelatinous matrix). The cases of multicanalicular vestibular
lithiasis with the involvement of more than one semicircular canal require meticulous
identification of the involved canals and multiple different canal-clearing maneuvers
for effective treatment. A 70-year-old male patient with no significant history of
previous medical or otologic illnesses or head trauma presented with a 1-day history
of vertigo with positional aggravation. A one-time performed diagnostic supine head
roll test elicited three different patterns of positional nystagmus, each with an
accurate localizing and lateralizing value. Diagnosis of unilateral multicanalicular
vestibular lithiasis of right horizontal and posterior semicircular canals was entertained
based on the pattern of the elicited positional nystagmi on the supine roll test.
The upbeating torsional nystagmus that localizes the involvement to the posterior
semicircular canal was paradoxically elicited by supine head roll test and not by
the Dix–Hallpike test. As horizontal semicircular canalolithiasis causes severe symptoms,
its treatment preceded that of concurrent posterior semicircular canalolithiasis.
The patient was successfully treated with multiple sessions of canalith repositioning
maneuvers (CRMs) spread over 24 hours. It is important to perform both positional
tests, namely Dix–Hallpike maneuver, and supine head roll test, in cases suspected
to have multicanalicular vestibular lithiasis. The positionings may need to be repeated
several times to unveil multiple nystagmi, each with different localizing and lateralizing
values. Identifying treatment priorities with CRM for the individual semicircular
canals is crucial, and the canal that is liable to cause severe symptoms needs early
clearance of the otoconial debris. If a CRM fails to clear a semicircular canal, an
alternative maneuver may need to be executed. Clinicians involved in the care of cases
with multicanalicular vestibular lithiasis should be well versed with all possible
backup maneuvers for clearing each of the three semicircular canals.
Keywords
vestibular lithiasis - multicanalicular - otoconial debris - BPPV - Dix–Hallpike test
- supine head roll test
